Decreased Expression of miR-548c-3p in Osteosarcoma Contributes to Cell Proliferation Via Targeting ITGAV.

The members of the integrin αv (ITGAV) family are widely expressed on many types of tumors and have been reported to be involved into angiogenesis, tumor metastases, and multicellular radioresistance. Osteosarcoma (OS) is the most common primary malignant bone tumor and the role of ITGAV in OS needs to be further elucidated. MicroRNAs are aberrantly expressed in a variety of cancers. Thus, the authors collected OS tissues (n = 15) and corresponding paracancerous tissues (n = 15) and found that the expression of miR-548c-3p was significantly downregulated in OS tissues and cell lines 143B, SaoS2, and HOS when compared to the corresponding paracancerous tissues and human osteoblast cell line hFOB (OB3), respectively. In addition, the authors identified that miR-548c-3p could directly target the 3'-untranslated region of ITGAV, and miR-548c-3p overexpression inhibits the mRNA and protein levels of ITGAV, which were confirmed by the luciferase reporter assays. Interestingly, they also uncovered that miR-548c-3p overexpression or knockdown of ITGAV remarkably suppressed cell vitality and promoted apoptosis and G2/M cell cycle arrest, leading to abrogating the ability of colony formation. The results indicated that the miR-548c-3p, similar to the target agents against integrin αv in clinical trials, could negatively regulate the ITGAV and be a promising tumor therapeutic target.